A Cross-sectional Study on the Effect of Second-generation Anti-histamines on Attention and Concentration in Patients with Chronic Urticaria

Background: Second-generation H 1 -anti-histamines (SGAHs) are recommended as first-line treatment, with up-dosing up to fourfold for patients with inadequate control. SGAH are generally considered non-sedating. Although SGAH are considered non-sedating, evidence on their cognitive effects at higher doses is limited. Objective: The primary objective is to compare the effects of standard-dose SGAH and high-dose SGAH on attention and concentration in patients with chronic urticaria (CU). The secondary objective is to determine the effect of CU severity on attention and concentration and to assess the impact of CU on sleep and quality of life. Materials and Methods: The study was conducted at the Dermatology Clinic, Hospital Melaka between November 2024 and May 2025. Seventy-four patients were recruited, with 37 patients in the standard-dose arm and 37 patients given doses higher than the licensed dose. Cognitive performance was assessed using the digit symbol substitution test (DSST) and digit span test (DST). Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI) and quality of life with the CU quality-of-life questionnaire (CU-Q2oL). Disease severity was measured using Urticaria Activity Score and Itch Verbal Rating Score. Results: DSST scores were lower in the high-dose SGAH group compared to standard-dose SGAH group, but not significant (47.05 ± 6.34 vs. 49.14 ± 6.23, P = 0.159). There was no significant difference in DST scores between these two groups. Among all the study patients, PSQI score was 4.81 ± 2.58. CU-Q2oL score was 36.61 ± 12.88. Conclusion: Up-dosing SGAH did not impair attention or concentration, quality of life was primarily influenced by disease severity and itch.